Objectif The main objective of the R&D programme is to optimize seismic reflection acquisition methods for accurate delineation of shallow deposits in a macro model and, by using this information, to improve the quality of deep seismic reflection data.Use will be made of full elastic data analyse and data processing techniques for the determination of the macromodel of the shallow subsurface.Much attention will be paid to facilities for quality control (acquisition procedure and data).A data acquisition procedure and a data processing sequence for the estimation of detailed macro models of the shallow subsurface has been defined. Development needs were identified and the project plan for the R&D work.In phases 1 and 2 of the project an evaluation of existing technology for possible use in the R&D programme was carried out. The following aspects were considered :1) data acquisition procedure;2) data acquisition systems;3) sources and receivers.The conclusions of this evaluation are summarized hereunder.1. For determination of macromodels of the shallow subsurface useful information is provided by P and S reflected waves.Both waves can be generated by burried explosives. The data can be acquired by recording two components over a sufficient long spread in order to obtain P-S conversions.2. Data acquisition system that allow to perform high resolution seismic surveys do not meet the requirements for :- modern data acquisition procedures;- high data quality;- high productivity.Major shortcomings of existing systems are :- not sufficient quality control provided (data and system quality control);- they are too bulky, heavy and expensive to be used for high resolution seismic surveys.3. Existing sources and receivers satisfy the requirements set by the high resolution seismic method.Deep seismic reflection surveys for hydrocarbons exploration and reservoir delineation are severly hampered in areas with a complex shallow subsurface, due to raybending. For the removal of the effect of raybending detailed information about the structure and the seismic parameters of the shallow deposits is needed (detailed macromodel). This information can be obtained by optimising high resolution seismic reflections methods, for the determination of this detailed macromodel. In numerous cases this accurate knowledge about shallow deposits is indispensable for the interpretation and inversion of deep seismic data.The important improvements that have to be realized for the efficient determination of an accurate macromodel of the shallow subsurface are:- development of a data acquisition system for efficient recording of two component high resolution seismic data of high quality utilizing the proposed data acquisition procedures.- developments of techniques for the determination of a detailed macromodel of the shallow subsurface applying for the inversion of techniques on two component shot data.The acquisition system main developments include extensive data quality control facilities (incl. automatic position determination of remote units) implemented on a PC based open central unit. Concerning the remote units, attention is paid to the development of light weight cost effective units, by miniaturization of the electronics and realizing the power supply over the field cable.For the determination of macro models from the acquired data the following processing steps must be adapted for pre-stack shot ordered data :- decomposition of two component data set in P and S waves;- estimation of coupled P/S macromodel;- macromodel verification.The developed techniques and instrumentation will be field tested. Programme(s) ENG-HYDROCARB 2C - Programme (EEC) of support for technological development in the hydrocarbons sector, 1986-1989 Thème(s) 1.4 - GEOPHYSICS AND PROSPECTING Appel à propositions Data not available Régime de financement DEM - Demonstration contracts Coordinateur TNO Institute of Applied Geoscience Contribution de l’UE Aucune donnée Adresse Schoemakerstraat 97 2600 JA Delft Pays-Bas Voir sur la carte Coût total Aucune donnée
